org.apache.pdfbox.io

Class NonSeekableRandomAccessReadInputStream

java.lang.Object

org.apache.pdfbox.io.NonSeekableRandomAccessReadInputStream

All Implemented Interfaces:

Closeable, AutoCloseable, RandomAccessRead

public class NonSeekableRandomAccessReadInputStream
extends Object
implements RandomAccessRead

An implementation of the RandomAccessRead interface using an InputStream as source. It is optimized for a minimal memory footprint by using a small buffer to read from the input stream instead of copying the whole input stream to memory. This reduces the random access read abilities, so that peek/rewind operations are limited to the data within the buffer. This class is meant to be used by consumers which process the data more or less in a serial manner and therefore don't need full random access.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	currentBufferPointer
protected long	position
protected long	size

Constructor Summary

Constructors

Constructor and Description
NonSeekableRandomAccessReadInputStream(InputStream inputStream) Default constructor.

Method Summary

Modifier and Type	Method and Description
protected void	checkClosed() Ensure that the RandomAccessBuffer is not closed
void	close()
RandomAccessReadView	createView(long startPosition, long streamLength) Creates a random access read view starting at the given position with the given length.
long	getPosition() Returns offset of next byte to be returned by a read method.
boolean	isClosed() Returns true if this source has been closed.
boolean	isEOF() A simple test to see if we are at the end of the data.
long	length() The total number of bytes that are available.
int	read() Read a single byte of data.
int	read(byte[] b, int offset, int length) Read a buffer of data.
void	rewind(int bytes) Seek backwards the given number of bytes.
void	seek(long position) Seek to a position in the data.
void	skip(int length) Skips a given number of bytes.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.pdfbox.io.RandomAccessRead

available, peek, read

Field Detail

position

protected long position

currentBufferPointer

protected int currentBufferPointer

size

protected long size

Constructor Detail

NonSeekableRandomAccessReadInputStream

public NonSeekableRandomAccessReadInputStream(InputStream inputStream)

Default constructor.

Method Detail

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

seek

public void seek(long position)
          throws IOException

Seek to a position in the data.

Specified by:

seek in interface RandomAccessRead

Parameters:

position - The position to seek to.

Throws:

IOException - If there is an error while seeking.

skip

public void skip(int length)
          throws IOException

Description copied from interface: RandomAccessRead

Skips a given number of bytes.

Specified by:

skip in interface RandomAccessRead

Parameters:

length - the number of bytes to be skipped

Throws:

IOException - if an I/O error occurs while reading data

getPosition

public long getPosition()
                 throws IOException

Returns offset of next byte to be returned by a read method.

Specified by:

getPosition in interface RandomAccessRead

Returns:

offset of next byte which will be returned with next RandomAccessRead.read() (if no more bytes are left it returns a value >= length of source)

Throws:

IOException - If there was an error while getting the current position

read

public int read()
         throws IOException

Read a single byte of data.

Specified by:

read in interface RandomAccessRead

Returns:

The byte of data that is being read.

Throws:

IOException - If there is an error while reading the data.

read

public int read(byte[] b,
                int offset,
                int length)
         throws IOException

Read a buffer of data.

Specified by:

read in interface RandomAccessRead

Parameters:

b - The buffer to write the data to.

offset - Offset into the buffer to start writing.

length - The amount of data to attempt to read.

Returns:

The number of bytes that were actually read.

Throws:

IOException - If there was an error while reading the data.

length

public long length()
            throws IOException

The total number of bytes that are available.

Specified by:

length in interface RandomAccessRead

Returns:

The number of bytes available.

Throws:

IOException - If there is an IO error while determining the length of the data stream.

rewind

public void rewind(int bytes)
            throws IOException

Description copied from interface: RandomAccessRead

Seek backwards the given number of bytes.

Specified by:

rewind in interface RandomAccessRead

Parameters:

bytes - the number of bytes to be seeked backwards

Throws:

IOException - If there is an error while seeking

checkClosed

protected void checkClosed()
                    throws IOException

Ensure that the RandomAccessBuffer is not closed

Throws:

IOException - If RandomAccessBuffer already closed

isClosed

public boolean isClosed()

Returns true if this source has been closed.

Specified by:

isClosed in interface RandomAccessRead

Returns:

true if the source has been closed

isEOF

public boolean isEOF()
              throws IOException

A simple test to see if we are at the end of the data.

Specified by:

isEOF in interface RandomAccessRead

Returns:

true if we are at the end of the data.

Throws:

IOException - If there is an error reading the next byte.

createView

public RandomAccessReadView createView(long startPosition,
                                       long streamLength)
                                throws IOException

Description copied from interface: RandomAccessRead

Creates a random access read view starting at the given position with the given length.

Specified by:

createView in interface RandomAccessRead

Parameters:

startPosition - start position within the underlying random access read

streamLength - stream length

Returns:

the random access read view

Throws:

IOException - if something went wrong when creating the view for the RandomAccessRead